First of all, to those who find the flashbacks confusing or even claim they ruin the show - this is pure ignorance. The flashbacks were obvious by they were filmed (so not confusing at all), and they were relevant to the story. To those who think the show was slow - you're just impatient.
Anyone with a average IQ common sense can follow this plot and understand how the flashbacks are necessary to the series.
The acting wasn't Oscar worthy, but it wasn't bad - it was on par with a Hulu series. PTSD was well portrayed (bravo!). And in the final episode we learn exactly what happened to Alison. No, there was no eye witness in the series to what happened to her, but her sister came to a reasonable conclusion after compiling the facts of that night she knew to be true.
The ending was, I think, unexpected, a relief (by how it differed compared to the expectation that was set throughout the entire series), and sad. I'd be happy to watch a season 2... I'd love to understand why Claire moved to the west coast to a family that has yet to heal from the trauma they all experienced, and why she left s boyfriend who loved her. So, please give us a season two and continue to develop these characters!